Experimental Investigation on Ignition and Lean Blow-out Performance of a Multi-sector Centrally Staged Combustor

Improvement on extinction and pollution emission have become one of the most prominent research topics in gas turbine.It is widely recognized that the fuel/air mixture distribution in the recirculation zone is a critical factor in improving lean blow-out(LBO) and ignition.This paper proposed a new low emission scheme with fuel staged centrally and hybrid injector to improve flameout and emission.A relative small amount of fuel enters into central pilot airblast atomizer burner and then atomized by inner swirl air.The remaining majority of fuel is directly injected into vane channels of the primary swirler through a series of holes located on the sidewall of the main stage.Only pilot stage is fueled under ignition and lean flameout condition.The uniformity of fuel/air mixture distribution in the primary zone of the new design decreases NOX emission,meanwhile the fuel air mixture in pilot recirculation zone is locally rich to improve flameout and ignition.Experimental investigation was conducted to compare the new scheme with baseline design of dual-swirler in terms of LBO and ignition characteristics under the same condition in a multi-sector combustor.It is found that the fuel-air ratio of ignition limit and LBO decrease with the reference velocity increasing.The experimental results also show that the new scheme successfully improve lean blow-out and broaden the operation range of the combustor.The experimental results indicated that the centrally staged scheme can widen the operation boundary of the combustor and can provide guidance for design and optimization of combustion chamber.

Update in lean metabolic dysfunction-associated steatotic liver disease

BACKGROUND A new nomenclature consensus has emerged for liver diseases that were previously known as non-alcoholic fatty liver disease(NAFLD)and metabolic dysfunction-associated fatty liver disease(MAFLD).They are now defined as metabolic dysfunction-associated steatotic liver disease(MASLD),which includes cardiometabolic criteria in adults.This condition,extensively studied in obese or overweight patients,constitutes around 30%of the population,with a steady increase worldwide.Lean patients account for approximately 10%-15%of the MASLD population.However,the pathogenesis is complex and is not well understood.AIM To systematically review the literature on the diagnosis,pathogenesis,characteristics,and prognosis in lean MASLD patients and provide an interpretation of these new criteria.METHODS We conducted a comprehensive database search on PubMed and Google Scholar between January 2012 and September 2023,specifically focusing on lean NAFLD,MAFLD,or MASLD patients.We include original articles with patients aged 18 years or older,with a lean body mass index categorized according to the World Health Organization criteria,using a cutoff of 25 kg/m2 for the general population and 23 kg/m2 for the Asian population.RESULTS We include 85 studies in our analysis.Our findings revealed that,for lean NAFLD patients,the prevalence rate varied widely,ranging from 3.8%to 34.1%.The precise pathogenesis mechanism remained elusive,with associations found in genetic variants,epigenetic modifications,and adaptative metabolic response.Common risk factors included metabolic syndrome,hypertension,and type 2 diabetes mellitus,but their prevalence varied based on the comparison group involving lean patients.Regarding non-invasive tools,Fibrosis-4 index outperformed the NAFLD fibrosis score in lean patients.Lifestyle modifications aided in reducing hepatic steatosis and improving cardiometabolic profiles,with some medications showing efficacy to a lesser extent.However,lean NAFLD patients exhibited a worse prognosis compared to the obese or overweight counterpart.CONCLUSION MASLD is a complex disease comprising epigenetic,genetic,and metabolic factors in its pathogenesis.Results vary across populations,gender,and age.Limited data exists on clinical practice guidelines for lean patients.Future studies employing this new nomenclature can contribute to standardizing and generalizing results among lean patients with steatotic liver disease.

Heterostructured nickel-cobalt metal alloy and metal oxide nanoparticles as a polysulfide mediator for stable lithium-sulfur full batteries with lean electrolyte

Batteries that utilize low-cost elemental sulfur and light metallic lithium as electrodes have great potential in achieving high energy density.However,building a lithium-sulfur(Li-S)full battery by controlling the electrolyte volume generally produces low practical energy because of the limited electrochemical Li-S redox.Herein,the high energy/high performance of a Li-S full battery with practical sulfur loading and minimum electrolyte volume is reported.A unique hybrid architecture configured with Ni-Co metal alloy(NiCo)and metal oxide(NiCoO_(2))nanoparticles heterogeneously anchored in carbon nanotube-embedded selfstanding carbon matrix is fabricated as a host for sulfur.This work demonstrates the considerable improvement that the hybrid structure's high conductivity and satisfactory porosity promote the transport of electrons and lithium ions in Li-S batteries.Through experimental and theoretical validations,the function of NiCo and NiCoO_(2) nanoparticles as an efficient polysulfide mediator is established.These particles afford polysulfide anchoring and catalytic sites for Li-S redox reaction,thus improving the redox conversion reversibility.Even at high sulfur loading,the nanostructured Ni-Co metal alloy and metal oxide enable to have stable cycling performance under lean electrolyte conditions both in half-cell and full-cell batteries using a graphite anode.

Metal-free two-dimensional phosphorene-based electrocatalyst with covalent P-N heterointerfacial reconstruction for electrolyte-lean lithium-sulfur batteries

The use of lithium-sulfur batteries under high sulfur loading and low electrolyte concentrations is severely restricted by the detrimental shuttling behavior of polysulfides and the sluggish kinetics in redox processes.Two-dimensional(2D)few layered black phosphorus with fully exposed atoms and high sulfur affinity can be potential lithium-sulfur battery electrocatalysts,which,however,have limitations of restricted catalytic activity and poor electrochemical/chemical stability.To resolve these issues,we developed a multifunctional metal-free catalyst by covalently bonding few layered black phosphorus nanosheets with nitrogen-doped carbon-coated multiwalled carbon nanotubes(denoted c-FBP-NC).The experimental characterizations and theoretical calculations show that the formed polarized P-N covalent bonds in c-FBP-NC can efficiently regulate electron transfer from NC to FBP and significantly promote the capture and catalysis of lithium polysulfides,thus alleviating the shuttle effect.Meanwhile,the robust 1D-2D interwoven structure with large surface area and high porosity allows strong physical confinement and fast mass transfer.Impressively,with c-FBP-NC as the sulfur host,the battery shows a high areal capacity of 7.69 mAh cm^(−2) under high sulfur loading of 8.74 mg cm^(−2) and a low electrolyte/sulfur ratio of 5.7μL mg^(−1).Moreover,the assembled pouch cell with sulfur loading of 4 mg cm^(−2) and an electrolyte/sulfur ratio of 3.5μL mg^(−1) shows good rate capability and outstanding cyclability.This work proposes an interfacial and electronic structure engineering strategy for fast and durable sulfur electrochemistry,demonstrating great potential in lithium-sulfur batteries.

Effect of nano-CaO particle on the microstructure,mechanical properties and corrosion behavior of lean Mg-1Zn alloy

The effects of nano-CaO contents on the microstructure,mechanical properties and corrosion resistance of lean Mg-1Zn alloy were investigated.The results showed that the addition of nano-CaO significantly refined the grain size and improved mechanical properties of the Mg-1Zn alloy.At the same time,CaO reacted with molten Mg in situ to form nano-MgO,whose corrosion product in SBF solution was the same with the degradation product of Mg matrix,resulting in the enhanced compactness of the Mg(OH)_(2) layer and reduced corrosion rate of matrix.The Mg-1Zn alloy had lower corrosion resistance due to excessively large grain size and shedding of corrosion products.The composite with 0.5 wt.%CaO had the best corrosion resistance with a weight loss of 9.875 mg·y^(-1)·mm^(-2)due to the small number of Ca_(2)Mg_(6)Zn_(3) phase and suitable grain size.While for composites with high content of CaO(0.7 wt.%and 1.0 wt.%),they had lower corrosion resistance due to the coexistence of large number of Ca_(2)Mg_(6)Zn_(3) and Mg_(2)Ca at grain boundaries,especially for 1.0 wt.%CaO composite,resulting from the strong micro-galvanic corrosion.

Overview of the Theoretical Exploration and Application of Lean Six Sigma

In contemporary contexts,Lean Six Sigma(LSS)is extensively utilized and has evolved across various sectors due to its substantial benefits.This paper aims to explore the definition,origin,and development of LSS,as well as its key tools,methods,theoretical research,and future prospects.Furthermore,it analyzes the theoretical foundations and practical applications of LSS in-depth,with an emphasis on anticipating future development trends.The goal is to provide readers with a comprehensive overview of LSS and offer insights for enterprises seeking to implement LSS for process improvement and innovation.

NO reduction by CO over TiO_2-γ-Al_2O_3 supported In/Ag catalyst under lean burn conditions

TiO2/γ-Al2O3 supported In/Ag catalysts were prepared by impregnation method,and investigated for NO reduction with CO as the reducing agent under lean burn conditions.The microscopic structure and surface properties of the catalysts were studied by N2 adsorption-desorption,X-ray diffraction,transmission electron microscopy,X-ray photoelectron spectroscopy,ultraviolet-visible spectroscopy,H2 temperature-programmed reduction and Fourier transform infrared spectroscopy.TiO2/γ-Al2O3 supported In/Ag is a good catalyst for the reduction of NO to N2.It displayed high dispersion,large amounts of surface active components and high NO adsorption capacity,which gave good catalytic performance and stability for the reduction of NO with CO under lean burn conditions.The silver species stabilized and improved the dispersion of the indium species.The introduction of TiO2 into the γ-Al2O3 support promoted NO adsorption and improved the dispersion of the indium species and silver species.

基于ARM和TCP/IP Lean的智能家居控制器的研究

为了进一步提高人们的生活质量,设计了一种成本低廉、面向家庭的远程智能家居控制器,主要用于控制电灯、电冰箱、空调等家用电器的运行状态。采用ARM处理器S3C44B0作为核心处理单元,硬件平台由S3C44B0和以太网控制器CS8900等器件组成,软件主要以精简TCP/IP协议栈为核心,两者共同组建了嵌入式智能家居Web服务器。在网络畅通的情况下,用户通过点击嵌入在硬件平台的Web页面上的按钮来控制相应的家用电器。

Lean 6 Sigma方法优化放射学工作流程的应用体会

在HIS/PACS/RIS集成构建中应用Lean6sigma方法,找出传统放射科工作流程中影响工作效率和质量的关键影响因素,再应用精益的方法消除影响工作流程的"浪费"现象,设计能持续发展的解决方案,优化放射科工作流程,提高放射科室的工作效率,为数字化医院的内在流程建设提供宝贵的实施经验和方法。

基于E-leaning的体育课程网络化教学改革

E-leaning可以优化教育资源、提高学习效率、降低学习成本,对于体育课程教学而言,其灵活便捷的教学方式能够解决"学训矛盾",方便学生自主学习。学习过程记录方便、教学管理和课程资源及时有效的更新,既方便了教学管理,也为体育远程教育创造了条件。E-leaning借助网络跨越了校园空间的限制,给学习者提供了一个全新的学习环境,促使了学校与学习者之间距离的缩短,让学校教育向更广泛的地区辐射。借助E-leaning进行体育精品课程和网络课程整合,开展体育远程教育有助于现有体育精品课程和网络课程的可持续发展,有利于体育教育资源共享,是未来学校体育教育和终身体育教育的重要途径。

基于爬虫和LeanCloud数据存储的双语阅读平台设计

针对移动开发者在移动应用开发的过程中,经常需要用到大量数据信息的问题,提出一种利用爬虫技术获取网络上的数据,并结合Lean Cloud进行数据存储,从而为开发者提供海量数据的技术方案。Jsoup是用Java语言开发的知名度较高的Java第三方类库,已经成为Java爱好者解析HTML文档的首选之一,并被广泛用于网络爬虫抓取海量网络数据。文中以Android双语阅读平台为例,通过Jsoup网络爬虫抓取网络数据和Lean Cloud进行数据存储开发了一款Android双语阅读平台,软件响应速度快、信息处理速度快。

《Leaning to do》的启示:把价值观教育与TVET结合起来

这几个模块相关联的核心价值是健康,与自然和谐,达到人的身体、智力、情感、社会和精神的全面发展,实现一种人与人、人与自然环境和谐的状态.要对自身健康负责,对所有形态的生命关爱,成为一个环境的看护者.

IPD模式下基于VisiLean的施工生产计划与控制研究

为完善IPD模式实践应用的操作系统,引入集成精益建造与BIM技术的施工生产管理系统VisiLean,构建IPD模式下基于VisiLean的施工生产计划与控制系统的基本框架,并对系统框架下的操作流程进行详细的阐述,该体系可以有效提高施工生产计划的可靠性,维护生产流的稳定性,对于IPD模式下建造流程的持续改进具有一定的指导意义。

Lean diabetes mellitus:An emerging entity in the era of obesity

Much has been published on the characteristics of type 2 diabetes mellitus and its association with the epidemic of obesity.But relatively little is known about the incidence of lean diabetes,progression of disease and fate of the patients with low-normal body mass index(< 25).Studies in developing countries have shown that the clinical characteristics of these patients include history of childhood malnutrition,poor socioeconomic status,relatively early age of onset and absence of ketosis on withdrawal of insulin.In the United States,recent studies showed that the lean,normal weight diabetes is not rare especially among minority populations.They showed that these patients are mainly males,have higher prevalence of insulin use indicating rapid beta cell failure.They might have increased total,cardiovascular and non cardiovascular mortality when compared to obese diabetic patients.In this review,the epidemiologic and clinical features of lean diabetes are presented.The potential causal mechanisms of this emerging diabetes type that may include genetic,autoimmune,acquired and behavioral factors are discussed.The need for studies to further elucidate the causation as well as specific prevention and treatment of lean diabetes is emphasized.

Lean Cuisine+规范图形界面自动分析软件的设计和实现

Auto-Generation Software是作者开发的一种图形界面自动分析软件,它可以从Delphi所开发的图形用户界面中自动萃取与生成LeanCuisine+图表,并最终生成的Lean Cuisine+文件可以按文本方式进行修改,而且能被Lean Cuisine+支撑环境SELCU所识别,并在其图形化的环境下进行操作。提供了一个符合Lean Cuisine+规范的完整图形用户界面早期设计环境。

Influence of hot rolling on the microstructure of lean duplex stainless steel 2101

In this work, the microstructure and the strain partitioning of lean duplex stainless steel 2101 (LDX 2101) during different hot-rolling processes are investigated by optical microscopy and electron-backscattered diffraction (EBSD). The results show that the LDX 2101 exhibits poor thermoplasticity at high temperature. The four-pass hot-rolled plates show fewer edge-cracking defects and superior thermoplasticity compared with the two-pass hot-rolled plates prepared at different temperature. The phase boundary is the weakest site in the LDX 2101. The cracks are initiated and propagated along the phase boundaries during the hot-rolling process. According to the EBSD analysis, the increase of the hot-rolling pass can dramatically improve the strain distribution in ferrite and austenite phases and promote the strain transmission in the constituent phases, thereby improving the coordinated deformation ability of the two phases. This effect further in- creases the thermoplasticity and reduces the formation of edge cracks in LDX 2101.

Lean techniques for the improvement of patients' flow in emergency department

BACKGROUND: Emergency departments(EDs) face problems with overcrowding, access block, cost containment, and increasing demand from patients. In order to resolve these problems, there is rising interest to an approach called "lean" management. This study aims to(1) evaluate the current patient flow in ED,(2) to identify and eliminate the non-valued added process, and(3) to modify the existing process.METHODS: It was a quantitative, pre- and post-lean design study with a series of lean management work implemented to improve the admission and blood result waiting time. These included structured re-design process, priority admission triage(PAT) program, enhanced communication with medical department, and use of new high sensitivity troponin-T(hsTnT) blood test. Triage waiting time, consultation waiting time, blood result time, admission waiting time, total processing time and ED length of stay were compared.RESULTS: Among all the processes carried out in ED, the most time consuming processes were to wait for an admission bed(38.24 minutes; SD 66.35) and blood testing result(mean 52.73 minutes, SD 24.03). The triage waiting time and end waiting time for consultation were significantly decreased. The admission waiting time of emergency medical ward(EMW) was significantly decreased from 54.76 minutes to 24.45 minutes after implementation of PAT program(P<0.05).CONCLUSION: The application of lean management can improve the patient flow in ED. Acquiescence to the principle of lean is crucial to enhance high quality emergency care and patient satisfaction.

Electrolyte solvation chemistry for lithium-sulfur batteries with electrolyte-lean conditions

Lithium-sulfur(Li-S)batteries possess overwhelming energy density of 2654 Wh kg-1,and are considered as the next-generation battery technology for energy demanding applications.Flooded electrolytes are ubiquitously employed in cells to ensure sufficient redox kinetics and preclude the interference of the electrolyte depletion due to side reactions with the lithium metal anode.This strategy is capable of enabling long-lasting,high-capacity and excellent-rate battery performances,but it mask the requirements of practical Li-S batteries,where high-sulfur-loading/content and lean electrolyte are prerequisite to realize the energy-dense Li-S batteries.Sparingly and highly solvating electrolytes have emerged as effective yet simple approaches to decrease the electrolyte/sulfur ratio through altering sulfur species and exerting new reaction pathways.Sparingly solvating electrolytes are characterized by few free solvents to solvate lithium polysulfides,rendering a quasi-solid sulfur conversion and decoupling the reaction mechanisms from electrolyte quantity used in cells;while highly solvating electrolytes adopt highdonicity or high-permittivity solvents and take their advantages of strong solvation ability toward polysulfide intermediates,thereby favoring the polysulfide formation and stabilizing unique radicals,which subsequently accelerate redox kinetics.Both solvation chemistry approaches have their respective features to allow the operation of cells under electrolyte-starved conditions.This Review discusses their unique features and basic physicochemical properties in the working Li-S batteries,presents remaining technical and scientific issues and provides future directions for the electrolyte chemistry to attain highenergy Li-S batteries.

Thoughts and Exploration on Transformation and Upgrading of Tobacco Production Promoted by Lean Management

Tobacco-producing field should carry out research oriented by fined technology,fluent work procedure and satisfied effect,reinforce lean management promotion,optimize allocation of tobacco production technologies,employees and resources,and improve science and technology research and development in a premise of improving tobacco quality,stable tobacco texture,and increasing tobacco production profit,in order to highlight service function of cooperatives and advance sustainable development.

Prevalence,clinical characteristics,risk factors,and indicators for lean Chinese adults with nonalcoholic fatty liver disease

BACKGROUND Nonalcoholic fatty liver disease(NAFLD)is one of the most common chronic diseases in the world.Nowadays,the percentage of non-obese or lean patients with NAFLD is increasing.NAFLD in non-obese populations,especially the lean subgroup with a normal waist circumference(WC),might lead to more problems than obese individuals,as these individuals may not visit clinics for NAFLD diagnosis or ignore the diagnosis of NAFLD.If the precise characteristics of these populations,especially the lean subgroup,are identified,the clinicians would be able to provide more appropriate advice and treatment to these populations.AIM To investigate the prevalence,clinical characteristics,risk factors,and possible indicators for NAFLD in lean Chinese adults with a normal WC.METHODS People without diabetes mellitus or significant alcohol consumption who underwent routine health examinations were included.Their fatty liver index(FLI),abdominal ultrasonography results,and controlled attenuation parameter were all assessed.Genotyping for single-nucleotide polymorphisms associated with NAFLD was performed in another small group consisting of biopsy-proven NAFLD subjects and healthy controls.RESULTS A total of 2715 subjects who underwent routine health examinations were included in the study.Among 810 lean participants with a normal WC,142(17.5%)fulfilled the diagnostic criteria for NAFLD.Waist-height ratio,hemoglobin,platelets,and triglycerides were significant factors associated with the presence of NAFLD in these participants.The appropriate cut-off value of the FLI score in screening for NAFLD in the lean subjects with a normal WC was 25.15,which had a 77.8%sensitivity and 75.9%specificity.There was no significant difference in the single-nucleotide polymorphisms in the SIRT1,APOC3,PNPLA3,AGTR1,and PPARGC1A genes between lean subjects with and without NAFLD(P<0.05).CONCLUSION NAFLD is not uncommon in lean Chinese adults even with a normal WC.Metabolic factors,rather than genetic factors,may play important roles in the development of NAFLD in this population.A lower cut-off value of the FLI score in screening for NAFLD should be used for lean Chinese adults with a normal WC.